1. Field of the Invention
The present invention relates to a warper and, more precisely, to a defective yarn repairing device of a warper for removing a defective part from a yarn contained in a warp and repairing the yarn with improved efficiency.
2. Description of the Prior Art
A warper referred to herein is a machine used at a weaving factory for drawing yarns from numerous yarn packages on a creel, forming them into a warp and then making a warp beam by taking up the warp.
In general cases, the occurrence of fluff in a yarn forming a warp beam is a serious obstacle in the subsequent weaving process, because the presence of fluff hinders smooth warp shedding and/or causes considerable deterioration in the quality of a woven cloth. Therefore, whenever fluff is found even in a single yarn among numerous yarns comprising a warp, the warper has to be halted immediately for removal of the defective part and repair of the yarn from which the defective part is removed. Conventional and widely known fluff detectors used for such purpose include, for example, those disclosed in Japanese Patent Publication No. 6352/1968 and Japanese Utility Model Publication No. 11486/1968.
When a fluff detector has caused a warper to stop, it is necessary to find and mend the yarn containing fluff (hereafter to be referred to as "defective yarn") among the numerous yarns which form the warp. In actual operation, the search for and picking out of a defective yarn depends entirely on human eyesight and manual operation. However, there exist some known methods intended to reduce the trouble of manual operation to some extent by means of the improved fluff detector which is capable of ascertaining the location of a defective yarn in relation to the width of the warp. Examples of such devices include those disclosed in Japanese Patent Publications Laid-Open Nos. 239038/1986 and 108136/1987. The latter of the two inventions is capable of detecting the location of a defective yarn with high accuracy by means of projecting laser beams across the warp and detecting light reflected by fluff with a plurality of CCD cameras.
According to such a conventional art, the location of a defective yarn contained in the warp may be accurately ascertained, but a continuous process of pulling the defective yarn from the warp and removing the defective part has to be done manually, which still requires a high degree of skill for the repairing operation, making it on the whole troublesome. It is difficult to pick up a desired yarn by hand without any damage to other yarns, because a large number of yarns are very closely arranged in the warp. Furthermore, it often happens that wind pressure or other force causes fluff, which may have been sticking out from the surface of the yarn at the time it passed the detection range of the fluff detector, to be lying fiat on the yarn or moved around to the back of the warp, making the finding of the defective yarn itself extremely difficult when the yarn is going to be pulled.